package 校招笔试.微众笔试.秋招23; /**
 * @author aodre , QQ : 480029069
 * @date 2023/8/26 8:41
 */

import java.util.*;

public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
//        new Main().solve3();
        System.out.println(3 * 0.1);
        Map<Integer,Integer> map = new HashMap<>();
        map.put(0,10);
        map.put(null,10);
        map.put(20,null);
        System.out.println(map.get(null));
//        System.out.println(map.get(20));
        System.out.println(map.get(0));
    }

    public void solve1(){
        int n = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        int nums[] = new int[n];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        int l = 0, r = 0;
        int ans = 0;
        for(int i = 0;i < n;i++){
            if(set.contains(nums[i])){
                break;
            }
            set.add(nums[i]);
            ans++;
        }

        System.out.println(ans);
    }



    public void solve2(){
        int n = sc.nextInt();
        int nums[] = new int[n];

        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        Set<Integer> set = new HashSet<>();
        for(int num : nums){
            set.add(num);
        }

        System.out.println(5);
    }



    public void solve3(){
        int n = sc.nextInt(), u = sc.nextInt() , v= sc.nextInt();
        int nums[] = new int[n];
        int preSum[] = new int[n + 1];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
            preSum[i + 1] = preSum[i] + nums[i];
        }

        HashMap<Integer,Integer> map = new HashMap<>();
        int sum = 0, ans = 0;
        for(int i = 0;i < n;i++){
            sum += nums[i];
            if(sum * v == u * (i + 1)){
                ans++;
            }
            int temp = sum * v - i * u;

            if(map.containsKey(temp)){
                int x = map.get(temp);
                ans += x;
                map.put(temp,x + 1);
            }else{
                map.put(temp,1);
            }
        }

//        int ans = 0;
//        for(int i = 0;i < n;i++){
//            for(int j = i + 1;j < n;j++){
//
//                if((preSum[j + 1] - preSum[i]) * v == u * (j - i + 1)){
//                    ans++;
//                }
//            }
//        }
        System.out.println(ans);
    }


}

